1. Field of the Invention
The present invention relates to a perpendicular magnetic write head provided with a magnetic pole and a protective film that covers the magnetic pole from an air bearing surface side.
2. Description of the Related Art
In recent years, performance improvement of a magnetic write head is required because of the increasing surface writing density of a magnetic recording medium such as a hard disk (hereinafter referred to as “recording medium”). Accordingly, a perpendicular magnetic write head in which a signal magnetic field is set in a direction perpendicular to a surface of the recording medium attracts attention. This is because of the advantages that a linear recording density increases and data written into the recording medium is less affected by the influence of heat fluctuation.
The perpendicular magnetic write head is provided with a thin film coil that generates a magnetic flux, and so on, together with a main magnetic pole layer. The main magnetic pole layer includes a tip part (magnetic pole) of a microscopic width that generates a writing magnetic field (perpendicular magnetic field). The magnetic pole is covered with a protective film from an air bearing surface side.
As for a configuration of the perpendicular magnetic write head, it is proposed to use a protective film made of hard amorphous carbon, in order to improve a corrosion resistance and abrasion resistance of the magnetic pole (for example, see Japanese Patent Application Publication No. 2007-026506).
These days, since a distance (fly height) between the magnetic pole and the recording medium decreases extremely, the magnetic pole is much more likely to be in contact with the recording medium. Since such contact of the magnetic pole causes the protective film to peel off and the magnetic pole to be exposed therefrom, the magnetic pole is more likely to be damaged and corroded due to oxidation, etc. The corrosion trend is outstanding in particular when the magnetic pole is formed of a high saturated magnetic flux density material such as an iron-based alloy.